Process of fastening non-metallic elements to metal



C. F. DIECKMANN.`

PROCESS 0F FASTENING NON-METALLIC ELEMENTS T0 METAL.

APPLICATION FILED JAN.24, 1920.

ATTKS.

UNITED STATES PATENT OFFICE.

CARL F. DIECKMANN, 0F CHICAGO, ILLINOIS, ASSIGNOR TO EUGENE DIETZGEN'COM- PANY, 0F CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

PROCESS 0F FASTENING NON-METALLIC ELEMENTS T0 METAL.

Specification of Letters Patent.

Patented May 10,1921.

Application led January 24, 1920. Serial No. 353,789.

T 0 all whom 'it may concern:

Be it known that I, CARL F. DIECKMANN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Processes of Fastening Non-Metallic Elements to Metal, of which the following is a specification.

My invention relates to processes of fastening non-metallic elements such as wood, Celluloid, and the like to metal, especially sheet metal, without theaid of rivets,screws, or similar mechanical contrivances. Attempts have been made to do this by the aid of glue or other adhesives, but an adhesive cannot sink into metal and hence rcleases it too readily, especially if the nonmetallic element shrinks or expands. My process while applicable in a variety of cases, is very useful in the manufacture of slide rules and similar instruments used by draftsmen, estimators, and others. The object of the invention is to provide a process by which metallic and non-metallic elements may be readily and securely, fastened together without separate fastening devices,

It will be understood by those familiar with the manufacture of devices composed in whole or in part of wood or celluloid that no matter how great care is exercised in seasoning or otherwise preparing the material it nevertheless shrinks and wai-ps when in the manufactured article. In celluloid articles, including scales, it is extremely important that they shall no t shrink nor warp, and as a result of my invention the Wood or Celluloid is so securely fastened to the metallic element that the latter acts as a reinforcement for the former and effectually prevents either shrinking or warping. In fact, articles constructed according to my .process become practically unitary and maintain both their length and shape indefinitely. The purpose of my invention is to provide a processcapable of obtaining these desirable features.

I obtain this object in the manner illustrated in the accompanying drawings 1n Whichv 1 Figure l is a face view, partly in section, of the frame or body of a slide rule the center of which is of metal and the graduated marginal strips are nonmetallic-usually Celluloid. The parts are secured together according to my improved method.

Fig. 2 is a sectional View taken on line 2 2, Fig. 1.

Fig. 3 is a sectional view similar to Fig. 2, but shows in addition, the central slide, which in this case is also composed of metal and nonmetallic elements.

Fig. 4 is a face view of the slide shown in Fig. 3.

Like numerals denote like parts throughout the several views.

For illustrative purposes I have chosen to show the invention as applied to slide rules and in this particular case the invention is applied both for forming the body of the rule and the slide itself. Vith reference to the body, a plate or strip l is formed, ten inches in length, or whatever the length of the rule .is to be. It may be made of aluminum or other metal, or alloy and may be polished to any extent desired. Rows of holes 2 are punched along the marginal edges and filled with adhesive substance. These marginal edges are then inserted in rabbets 3 formed in the inner faces of the side strips et of the rule with the result that when the adhesive has solidified it forms a solid connection from one surface of the non-metallic element to the other through the holes in the metal. This results in a most rigid and reliable fastening of the parts together.

lith respect to the slide, a plate or flat sti-ip G is provided which may, as before, be polished and of desired composition. Holes 7 are punched in it and filled with adhesive. Two flat strips of non-metallic substance are then pressed against the surfaces of the metal strip, so as to cover the holes and place the non-metallic strips in Contact with the adhesive. The adhesive is then permitted to solidify, whereupon the parts will be found to be securely and permanently fastened together. y

For slide rule purposes, the strips 8 are not as wide as trip 6, thus in effect forming marginal tongues adapted to slide in grooves l0 formed on the inner sides of the strips 4. The surfaces of the non-metallic elements are duly graduated in the manner familiar to those who understand the principle of the slide rule.

wWhile wood or fiber may be employed as the lion-metallic material, a particularly good article is produced by employing celluloid and' employing a fluid Celluloid as the the ilav

. beting the non-metallic,

adhesive. ln Such Case, the fluid Celluloid apparently becomes integral with the other and hence when the device is finished, it is as if there were integral pins or cores passing through the holes in the metal and the result is a most durable and permanent assemblage. I have found that a rule made by my process can safely be guaranteed to be accurate in Calculations within extremely small limits.

It will be understood, of Course, that the method may be applied to the production of articles other than slide rules.

Having thus described my invention what I Claim as new and desire to secure by Letterslatent, is

1. The process of fastening metal to a non metallic rigid, non plastic element, consisting in forming holes in the metal, filling them with adhesive and placing the metal between contiguous surfaces of the non metallic element, whereby the adhesive forms a connection from one side to the other, passing through the holes.

2. The process of fastening a. metal plate to a non-metallic element consisting in rabrigid non plastic element so as to fit closely over the edge of the plate, forming apertures in that portion of the plate adapted to enter the rabbet, filling the apertures with an adhesive, and inserting the edge of the plate with its filled apertures into said rabbet.

3. The process of fastening av smooth metal plate to non plastic Celluloid consisting in rabbeting the Celluloid soas to fit Closely over the edge portion 'of the plate, forming apertures in that portion of the plate adapted to enter the rabbet, filling the apertures with liquid Celluloid and inserting the edge of the plate with its filled apertures into said rabbet and permitting the liquid Celluloid to harden and thereby render the portions of Celluloid on the two sides of the plate Virtually integral.

4. The process of fastening Celluloid to a Smooth fiat strip of metal consisting in forming apertures in the strip, filling them with fluid Celluloid, forming fiat surfaces on the Celluloid which is to be fastened, placing the solid Celluloid, surface to surface against the metal strip in position to cover the holes, and permitting the fluid Celluloid to harden.

In witness whereof, l have hereunto subscribed my name.

CARL r. niEcKMANN. 

